Robert Cryer is Professor of International and Criminal Law at the University of Birmingham Law School.

Let me say at the outset that I think that Kevin has done an excellent job on the book (as have OUP in its production). I should probably also say, in the interests of full disclosure, that I flatter to call myself a friend of Kevin’s and have enjoyed the discussions we have had over aspects of the book during its gestation. The book is exceptionally well researched and written, and fills a significant lacuna in the literature. It has a strong narrative flow, and skilfully entwines the historic and legal aspects of the cases. There are many rich seams to mine in the book, but I will limit myself to one, and one of the rare instances where I disagree with Kevin, at least a little. This is the issue of the legacy of the Tribunals.

We used to hear quite a lot about the Nuremberg legacy; often in terms that bemoaned its betrayal. The International Criminal Tribunals for Yugoslavia and Rwanda, and the Special Court for Sierra Leone are now all self-consciously attempting to shape their respective legacies. Sadly, it is not clear to me that, in spite of Telford Taylor’s hopes and desires, the Nuremberg Military Tribunals had much of a legacy. In contrast, in the book, Kevin is relatively upbeat about aspects of their legacy (although other aspects are characterised, rightly, as “a complete failure” (p.400)).

In particular, he says that the greatest success of the Tribunals were their inestimable contribution to the form and substance of international criminal law…[unlike the Nuremberg IMT they]…took the raw materials provided to them-the London Charter, the IMT judgment, Law No 10- and honed them unto a coherent system of criminal law, one in which crimes were divided into elements, modes of participation were precisely identified, and defences were made available but cabined within reasonable limits. The NMTs, in other words, were committed to treating international criminal law as criminal law first and international law second. That commitment almost certainly explains why judges who had little knowledge of international law were able, far more often than not, to reach substantive decisions concerning crimes, modes of participation, and defences that remain good law more than 60 years later (pp.400-401).

I am sympathetic to the idea that international criminal law is made up of all three parts of its moniker. On the other hand, as an international lawyer, as well as a criminal lawyer, it is difficult not to comment that prioritising one aspect over another can be problematic. The idea the book seems to be pointing towards is that as the judges had a ‘feel’ for criminal law, they came to basically the right results. However, in the end, the sources of international criminal law, though, are those of positive international law, not natural reason. We stray from that path at our peril, not least owing to the nullum crimen sine lege principle. The judgments of the NMTs (which do differ on many issues, as the book brings out with great depth and sophistication, but which shows the fallacy of reliance on right reason), are usually brief, to say the least, on the sources of international criminal law. There often is no real discussion of custom and the like to determine the position in international law. Of course, it can be countered that there was less of a corpus of international criminal law at the time, in particular with regard to principles of liability and defences. But the brevity of the judgments on sources should give us pause about whether they can really be called good positive law, at least then.

The other point that the book is making (and I hope Kevin will pull me up if I have mistaken him here) is that they reflect much of modern international criminal law. The book spends quite a large amount of time discussing the authority in which the judgments have been held, in particular before the ICTY, where there was a lively debate about the question in Erdemović (a debate which is recounted well at pp.375-377). However, there are two issues that need to be thought through on this. The first is whether the citation of the decisions of the NMTs in later cases reflects the authority which they were thought to have, rather than them being considered useful support for a proposition that was decided upon for other reasons. The second is the issue, more generally, of causation where the positions that States may have reached in Rome, or in other treaty negotiations, were at least similar to those reached in some of the cases before the NMTs.

Looking first at the issue of citation of the NMT’s jurisprudence, the book is meticulous in identifying examples of citation of those cases in later decisions. Rightly, this is leavened by reference to the times that the jurisprudence was referred to inaccurately, incompletely, or ignored (examples of all which abound inter alia, at pp.377, 378, 381-382). But the issue of influence is not a matter solely of counting quotes. As the legal realists, amongst others, have discussed, citation occurs for various reasons. It can come from anything from a genuine belief in the precedential authority of a pronouncement, to the purely pretextual (and for many reasons in between). Where reference is made to bolster a position that has been adopted on other grounds, the case has not been influential per se; it has been co-opted, rather than treated as authority. Given the number of occasions that the book identifies misstatements and selective citation of the jurisprudence of the NMTs, it can be questioned whether at least some of those references in the cases can be explained away as misunderstandings, rather than tactical. This is particularly the case where there are, as the book shows very well, contradictory, or at least inconsistent, findings on substantive issues in the various NMTs.

To take this a little further, the book’s optimism about the authority granted to the findings of the NMTs is shown by the (accurate) critique of US Court of Appeals for the Second Circuit’s decision in Presbyterian Church of Sudan v Talisman Energy 582 F.3d 244 (2nd Cir. 2009). The work takes the decision to task for asserting a purposive standard for the mens rea of aiding and abetting on the basis of one acquittal at the NMTs, when the vast preponderance of the NMTs decisions applied a knowledge-based standard. The book asserts that ‘[i]f this study had existed a few years ago, the court might have reached a very different conclusion’ (p.5). I would like to believe that it would have, but, as Kevin has repeatedly shown elsewhere, in particular on Opinio Juris (for a recent example, see here), citation by courts, in the US, as elsewhere, is often based on reasons far removed from a genuine investigation into the sources of international law and the relevant degree of authority that is to be attached to them.

Turning to the second issue; it is, of course, difficult to prove causation in international affairs, but I fear at times the work overstates the influence of the NMTs on States, describing them has having made “significant contributions” to the law of war crimes (p.380). For example, it is said that “the tribunals likely influenced the drafters of the Article 4(2) [of Geneva Convention III] concerning partisan activity in occupied territory” (ibid.). This is said to be “consistent” with the NMT jurisprudence. That is entirely true, but it does not prove causation. There is, for example, no reference to the jurisprudence of the NMTs in the Pictet commentary on GC III (which, admittedly, is not a record of the proceedings in Geneva, but is, nonetheless, hardly the rantings of a random scribbler either). What is, to me, at least as plausible, is that the issue was known about by the Allies owing to the practice in the Second World War rather than specifically being influenced by the case per se. The second example, that of the prohibition of killing hostages contained in GC IV was, as the book rightly points out, a complete repudiation of the position adopted in the Hostages case, so at best, it can be seen as a framing of the issues for States, rather than a contribution to the law.

When dealing with the drafting of other documents, this time the Rome Statute, again we have quite a strong claim, that “the Einsatzgruppen approach to duress had a considerable influence on the ICC”, in that “in contrast to ICTY jurisprudence, Article 31(1)(d) specifically permits a defendant to invoke duress as a defense to murder” (p.395). The latter statement is, in essence, true (the Article does not specifically permit the defence to murder, but it is probably implicit, and it is of no impact here). However, if the former assertion is taken to mean that the Einsatzgruppen case itself (rather than perhaps Erdemović which, admittedly, did discuss Einsatzgruppen) had an impact on the debate, I would have to express some considerable scepticism. The provision was a last ditch compromise in the final days of the Rome conference, and discussions at Rome on point did not did not focus on the post-war jurisprudence. It could be, though, that the quoted statement means that the approach adopted in Einsatzgruppen, rather than the case itself, was influential, but that takes us back to the beginning, that rather than authority, naturalism/reason was the inspiration for Article 31(1)(d). This would not be entirely inappropriate, because as States are entitled to create international law, they are entitled to bring their views into positive law by including it in Article 31(1)(d). That does not show the influence of the NMTs though.

The work of the NMTs was interesting. Equally, that does not mean that their output was or is always (good) international law, at least its sources are normally understood. It might be the case that sometimes the NMT’s jurisprudence has been considered, in and of itself, to be authoritative, but this is by no means always the case. The NMTs may have had some influence on modern international criminal law, but not in as strong a way as the book might imply. These are all, at least to me, fascinating issues, and I look forward to a discussion of them.